Fix JSON discriminator and nickname fields (#524)

DiscordChatExporter.Core/Discord/Data/User.cs

@@ -15,9 +15,11 @@ namespace DiscordChatExporter.Core.Discord.Data
 
         public int Discriminator { get; }
 
+        public string DiscriminatorFormatted => $"{Discriminator:0000}";
+
         public string Name { get; }
 
-        public string FullName => $"{Name}#{Discriminator:0000}";
+        public string FullName => $"{Name}#{DiscriminatorFormatted}";
 
         public string AvatarUrl { get; }
 

DiscordChatExporter.Core/Exporting/Writers/JsonMessageWriter.cs

@@ -169,7 +169,7 @@ namespace DiscordChatExporter.Core.Exporting.Writers
 
             _writer.WriteString("id", mentionedUser.Id.ToString());
             _writer.WriteString("name", mentionedUser.Name);
-            _writer.WriteNumber("discriminator", mentionedUser.Discriminator);
+            _writer.WriteString("discriminator", mentionedUser.DiscriminatorFormatted);
             _writer.WriteString("nickname", Context.TryGetMember(mentionedUser.Id)?.Nick ?? mentionedUser.Name);
             _writer.WriteBoolean("isBot", mentionedUser.IsBot);
 
@@ -228,7 +228,8 @@ namespace DiscordChatExporter.Core.Exporting.Writers
             _writer.WriteStartObject("author");
             _writer.WriteString("id", message.Author.Id.ToString());
             _writer.WriteString("name", message.Author.Name);
-            _writer.WriteString("discriminator", $"{message.Author.Discriminator:0000}");
+            _writer.WriteString("discriminator", message.Author.DiscriminatorFormatted);
+            _writer.WriteString("nickname", Context.TryGetMember(message.Author.Id)?.Nick ?? message.Author.Name);
             _writer.WriteBoolean("isBot", message.Author.IsBot);
             _writer.WriteString("avatarUrl", await Context.ResolveMediaUrlAsync(message.Author.AvatarUrl));
             _writer.WriteEndObject();